Triton is by far the largest of the planet Neptune’s thirteen known
moons. It was discovered by a wealthy brewery business owner and
amateur astronomer William Lassell. He was one of England’s premier
amateur astronomers of the 19th century, and used money from his
brewery business to finance the expensive telescopes necessary to
participate in his hobby much as adults today become involved in
costly extra-career endeavors. He spotted Triton through one of
these telescopes just days after Neptune’s official discovery in
1846. He also spotted a faint ring around the planet which was
proven to be an optical illusion caused by a distortion in the lens
of his telescope. While Neptune does have rings around it, they are
far too faint for Lassell to have actually seen them.

Satellites, or moons, of Neptune are all named for minor
mythological Greek sea gods or nymphs. Triton was the son of the
Greek sea god, Poseidon (counterpart to the Roman sea god, Neptune).
It has the unique distinction of being the only large moon in the
solar system that orbits its planet in the opposite direction of
that planet’s rotation. This is called a retrograde orbit. One side
of Triton faces the planet Neptune at all times. This is called a
synchronous rotation and is like the rotation of Earth’s moon. The
orbit of this large satellite is close to the shape of a perfect
circle with almost no elliptical peculiarities.

It is theorized that Triton may have one been a comet or asteroid
that was captured by the gravitational pull of Neptune. The
gravitational pull of its planet slows down its orbit, dragging it
ever closer to it. Perhaps millions of years from now, its orbit
will become so close to Neptune that the strong gravitational forces
will break it apart to form yet another ring around the planet.

Triton’s surface is made up of frozen Nitrogen over an icy layer
that is thought to cover a core of rock and metal. It is one of the
coldest objects in the solar system at approximately -400 degrees
Fahrenheit. When our exploratory spacecrafts passed Triton, it was
discovered that the moon has many active geysers on its surface –
possibly consisting of liquid Nitrogen. This activity is caused by
the sun’s heat hitting the moon at seasonal intervals in the year.
It is one of the few moons in the solar system with such activity.